1. Field of the Invention
The present invention relates to a rubber crawler mainly used for construction machines or civil engineering machines. More particularly, the present invention relates to a rubber crawler adopting a brand new structure as a tensile reinforcing member.
2. Background Technology
Conventionally, steel cords are embedded in a rubber crawler in a longitudinal direction of the rubber crawler to operate as tensile reinforcing members resisting tensile force applied thereto. However, in ordinary methods, when steel cords are formed in an endless manner, overlapped portions are formed between the steel cords. Due to this, there have been drawbacks in that a crawler operator can sense vibrations, and use of very high speed is impossible. Another the drawback has also been pointed out that steel cords, which are used as a tensile reinforcing member of a conventional rubber crawler, is easily broken when excessive tensile force is applied thereto.
Japanese Patent Application (JP-A) Laid-open No. 2000-313371 discloses a rubber crawler having a structure in which steel cords are not used. However, since in the rubber crawler in this disclosure all the core metals are of a type requiring assembly, problems are caused in that a lot of time and labor is necessary for manufacturing the rubber crawler and the rubber crawler does not exhibit excellent strength. Specifically, since considerably close attention must be paid especially when core metals and tensile reinforcing members are assembled, working efficiency is impaired. Further, since two bars are used at portions corresponding to wing portions of the core metals, comparatively fine materials should be used. For this reason, it can be predicted that problems such as deterioration of strength may occur. Moreover, since a connecting member for connecting these bars is structured to be comparatively easily elongated or the like, further improvements are required.
Accordingly, the present applicants are developing a rubber crawler having a brand new structure in which conventional steel cords are not used and instead, metallic connecting members are used as tensile reinforcing members such that the metallic connecting members are connected sequentially to wing portions of core metals adjacent to each other.
In the brand new rubber crawler, holes for sequential connection are formed in advance on wing portions of core metals, and connecting members having hooks at both sides thereof corresponding with the holes are used. The hooks are engaged with the corresponding holes. Accordingly, all the core metals are connected to one another in an endless manner, and then embedded in rubber. A rubber crawler is thus formed. In this rubber crawler, since the rubber crawler can be formed endlessly without using steel cords as a tensile reinforcing member, vibration or the like is improved, and high tensile strength is exhibited. However, in actuality, further improvements are required.
In the present invention, a rubber crawler is further improved such that a core metal has a simpler structure and an engaging member has a stronger structure.